1. Field of the Invention
This invention pertains to portable luggage carrying devices which can be folded or collapsed into a compact unit. The carrying device is pulled along behind the user rolling on two wheels and is adapted to transport easily even a plurality of bags, boxes or other similar articles.
2. Description of the Prior Art
Some devices of this type are known which are portable as collapsed in the form of a bundle, but the known devices involve problems attributable to the inherent structure thereof. Kazmark U.S. Pat. No. 3,612,563 (1971), for example, discloses a carrier which can be compacted to the form of a bundle when disassembled. This carrier is cumbersome to handle since the carrier must be disassembled, or conversely assembled for use. The device includes a suitcase support bracket of extremely small depth so as to be portable in a compact form. The device is unable to satisfactorily support a luggage of low rigidity because the bottom portion of the luggage is supported predominantly by a restraining strap. Since the luggage is placed on the support bracket with its center of gravity positioned outside the bracket because of the small depth, the handle bar is likely to forwardly fall down. Since the carrier has the support bracket as an elongated horizontal beam disposed outside two wheels diametrically outwardly thereof for supporting the wheels, the wheels remain projected when the carrier is in its folded state, hence bulky.
Shourek et al. U.S. Pat. No. 3,937,485 (1976) discloses a simple construction which, nevertheless, has inherent problems; a back portion or luggage support portion comprises a pair of telescopic tubular members which are difficult to hold in balance with each other when stretched, and the support portion fails to support the luggage with stability because it is triangular.
Kotani West German Laid-Open pat. application No. 27 45 177 discloses a carrier comprising a luggage support frame, a back frame and a pair of side assemblies provided on opposite sides of the carrier being adapted to hold both the frames approximately at a right angle with each other in an unfolded position, each of the side assemblies including a flexible slanting brace having one end connected to a front portion of the luggage support frame and the other end connected to a lower portion of the back frame. When the carrier is loaded with a luggage of poor rigidity, a flexible strap extending from a handle bar in the upper portion of the back frame to the front portion of the support frame is tightened up to restrain the luggage. The slanting braces then act against the restraining action of the taut strap, consequently subjecting the handle bar and the lower portion of the back frame to forces acting in opposite derections and causing damage to the back frame structure. Furthermore the carrier is unable to support luggages with a width larger than the entire width of the carrier due to the presence of the slanting braces. The proposed device therefore is not fully useful as a portable luggage carrier which must be usable for luggages of various character.
The prior art devices described above have problems in common. Although most of the luggages to be transported by the carriers of the type described are heavier than can be carried by hand, the carriers have no means whatever for overcoming the difficulties to be encountered in transport when they become unserviceable as wheeled devices in the course of transport. Whereas it has long been desired that the carrying devices of this type have outstanding portability along with various well-balanced useful features including the above-mentioned means and assuring a smooth transport operation, the known devices still remain to be improved in this respect.